The invention concerns an apparatus for bending a hollow section for producing a hollow spacer frame, filled with drying agent during or after bending, for insulating glass sheets, having a guide and retaining device approximately in the feed direction of the hollow section for grasping the region of the section situated before the bending point, having a device acting or serving as a bending tool for grasping and swivelling the leg of the hollow section to be bent around, and having an abutment for fixation of the inner side of the resulting bend or curvature. The apparatus optionally has a tool movable on the outer side of the bending point under surface pressure relative to the abutment and to the hollow section and pressable on the outer side of the hollow section and/or dipping between side bands of the hollow section, the tool being especially in the fonn of a pressure roller acting on at least one part of the section band situated on the outer side of the bend, wherein a support for a side band or a portion of a side band of the hollow section and parallel thereto a hold-down clamp for the other side band or a part of the other side band of this hollow section are provided. The distance between hold-down clamp and support corresponds approximately to the width of the hollow section and consequently to the subsequent clearance between two glass sheets to be held at a distance.
Such an apparatus for bending a space holding interior frame or spacer frame for an insulating glass sheet known from DE-B-32 21 986 as a component of a bending machine.
An apparatus of this type for bending a spacer frame filled with drying agent is furthermore known from EP-B-0 121 873, and a device of this type for bending a hollow section filled, or at first unfilled, with drying agent is known from EP-B-0 318 748. These devices have proven themselves because a bending of hollow sections with or without drying agent with a narrow bending angle is thereby possible, without the side bands being deformed in the bending area or containing deformations, and without the glass sheets to be placed thereon no longer being able to be kept at a distance and sealed off in a satisfactory manner and with sufficient exactitude.
Besides, with the previously known devices, chiefly extruded hollow sections with an indeed relatively thin wall thickness can be processed in a satisfactory manner. Nonetheless, a further diminution of wall thickness is not possible, since otherwise, despite this, an uncontrolled deformation of the side bands in the bending area cannot be ruled out. In addition, when bending hollow sections made of steel or stainless steel, it must be feared that in the bending area the side bands will lead to jamming between hold-down clamp and support in the bending area, or that the tightening and afterflow of the side band material will be hindered around the bend, so that the bending result is unsatisfactory, chiefly in the area of this side band.